【作者】 麻震宇；

【导师】 张为华；

【作者基本信息】 国防科学技术大学 ， 航空宇航科学与技术， 2012， 博士

【摘要】 本文以超空泡航行体为研究对象，以非线性有限元理论为基础，建立了超空泡航行体结构有限元模型，采用理论分析与流固耦合仿真相结合的方法，分析得到超空泡航行体结构的载荷特性，对复杂力学环境下的超空泡航行体结构动力学特性进行了系统深入的研究，为超空泡航行体结构设计提供了理论基础。结合水冲压发动机与水下航行体设计理论，提出了超空泡航行体的推进系统夹层结构布局，确定了超空泡航行体总体结构；针对超空泡航行体的滑行运动方式，对超空泡航行体进行受力分析，为开展超空泡航行体结构动力学研究提供了重要基础。采用相对自由度壳单元和等参实体单元建立超空泡航行体单层舱段有限元模型，推导了基于更新拉格朗日格式的航行体结构非线性有限元方程；采用单层等效模型、双层壳体模型和考虑流体影响的充液双层模型，建立了超空泡航行体夹层舱段有限元模型；基于间隙单元接触理论，建立了超空泡航行体轴向盘式连接和径向螺钉连接形式的舱段连接有限元模型。通过算例对航行体结构有限元模型进行了验证，为超空泡航行体结构动力学仿真提供了理论和方法基础。将结构入水理论与ALE有限元仿真方法相结合，建立超空泡航行体尾部流体动力载荷的理论模型和流固耦合仿真模型，计算得到航行速度和扰动角速度对超空泡航行体尾部载荷的影响规律，通过对比计算得到适用于超空泡航行体结构动力响应计算分析的载荷理论模型。基于更新拉格朗日格式的超空泡航行体结构有限元模型，将结构动力屈曲理论与非线性有限元方法相结合，开展了超空泡航行体结构动力屈曲研究。分析了航行速度和尾部沾湿面变化频率对结构动力失稳区域的影响，得到了舱段壳体厚度、夹层舱段结构参数和加强肋骨对超空泡航行体结构动力稳定性的影响规律，分析了舱段连接方式对结构动力稳定性的影响，为超空泡航行体结构动力学仿真研究提供了技术支撑。采用协同转动有限元理论与非保守系统稳定性理论相结合的方法，开展了超空泡航行体结构动力响应研究。分析了航行速度和扰动角速度对航行体结构动力响应的影响，获得了结构壳体厚度、夹层结构参数和加强肋骨对超空泡航行体结构动力响应的影响规律，为超空泡航行体结构减振设计提供了理论依据。本文研究成果将促进超空泡航行体技术发展，推动超空泡航行体结构动力学仿真技术进步，对超空泡航行体研制具有重要理论意义和工程应用价值。更多还原

【Abstract】 Under the background of the advance of the undewater vehicle technologies, aseries of structural dynamic problems are found during the development of thesupercavitating vehicle. In this paper, the finite element model was established for thesupercavitating vehicle based on the nonlinear finite element method. Systematical anddeep research was carried out on the structural dynamic characteristics of thesupercavitating vehilce, as well as on the interactions between the cavity and the vehiclebody, revealing the development process and the mechanisms of structural dynamicbuckling and dynamic response for the supercavitating vehicle, providing the theoreticalbasis for the structural design of the supercavitating vehicle.Based on the design theories of the water ramjet motor and the underwater vehicle,the structural configuration of double shells for the propulsive system of thesupercavitating vehicle was proposed and the general structural layout for thesupercavitating vehicle was confirmed. According to the planing motion configurationof the supercavitating vehicle the forces applied on the vehicle body were analyzed,providing the important basis for the numerical research on the structural dynamiccharacteristics of supercavitating vehicles.The plain shell structures of supercavitaiting vehicles were simulated by the shellelements of relative degrees of freedom and isoparameter solid elements, and thenonlinear finite element formulation based on the Updated Lagrange framework wasderived. The double shells structures of supercavitating vehicles were developed withthe equivalent monolayer model, the double layer model and the double liquid-filledmodel. Based on the gap element contact theory the finite element model of connectingstiffness was developed for the axial and radial connection configurations. The finiteelement model for the supercavitating vehicle was verifed by computing cases, and theabove research set the theoretical and method basis for the simulation on structuraldynamics of the supercaviting vehicle.The theoretical and numerical models of the hydrodynamic loads during theplaning of the supecavitating vehicle on the cavity were developed according to thetheory of water entry impact of the structure and the ALE finite element method. Theeffects of the velocity and the disturbance angular velocity of the supercavitatingvehicle on the hydrodynamic loads were analyzed and the theoretical model of thehydrodynamic loads for the structural dynamic response of supercavitating vehicles wasobtained by the comparison of the numerical results.Based on the finite element model of Updated Lagrange formulation, the numericalresearch on the structural dynamic buckling of supercavitating vehicles was performedusing the theory of structural buckling and nonlinear finite elemet method. The effects of velocity of the vehilce and the frequency of the wetted surface on the dynamicinstable regions were analyzed, and the thickness of the shell structures, the physicaldimensions of the double shells and the stiffeners configurations were investigated forthe mechanisms of structual dynamic stability, and the effects of the axial and radialconnection configurations on the structural dynamics was analyzed, providing technicalsupport for the development of numerical dynamics of structures of supercavitatingvehicles.The research on the structural dynamic response of supercavitating vehicles wascarried out using of the co-rotational formulation and non-conservative system stabilitytheory. The effect of velocity on the dynamic response was analyzed, and the thicknessof the shell structures, the physical dimensions of the double shells and the stiffenersconfigurations were investigated for the mechanisms of structual dynamic response. Theobained numerical results provide the theorical basis for the design of the structures forsupercavitating vehicles.The research achievements in this thesis will surely promote the develoment ofsupercavitating vehicles, as well as providing support for the advancement of thesimulation techniques for the structures of supercavitating vehicles. The research will beof great theoretical value as well as engineering practice meaning for the futuresupercavitatng vehicle design.更多还原